This invention is directed to aircraft autopilot systems and more particularly to aircraft autopilot systems utilized for automatically landing an aircraft.
In the past, various attempts have been made to provide autopilot systems suitable for controlling the landing of an aircraft. In general, these systems follow a glide slope beam toward a landing. While the prior art systems have been successful in some respects, a number of problems remain to be resolved. One of these problems relates to the beam distortions that may occur in the glide slope beam. By way of example, the glide slope beam may be distorted by large buildings surrounding the airport or by large aircraft moving in the vicinity of the airport. These distortions are received, along with the beam signal, by an aircraft attempting to follow the beam toward a landing and can cause the aircraft to change position rapidly. Such rapid aircraft maneuvers may be unsettling to the crew and passengers and, in some instances, may create dangerous landing situations. In any event, such beam distortions are changing and, generally, unpredictable. This invention is directed to overcoming such problems associated with the vertical (altitude) position of the aircraft.
Therefore, it is an object of this invention to provide a new and improved vertical glide slope control system.
It is a further object of this invention to provide a new and improved vertical glide slope control system suitable for use in aircraft automatic landing systems.
It is a still further object of this invention to provide a vertical glide slope control system suitable for use in aircraft automatic landing systems which eliminates unwanted effects of vertical glide slope beam distortions without degrading the stability of the aircraft.